Immunosuppressive Structure-Activity-Relationships Of Brequinar And Related Cinchoninic Acid-Derivatives

The immunosuppressive structure-activity relationships of substituted cinchoninic acid derivatives related to Brequinar were explored. Activities as inhibitors of dihydroorotate dehydrogenase and the mixed lymphocyte reaction were related to benzo-ring substitution, replacement of the benzo-ring by heterocycles, and variation in the 2-biphenyl, 3-methyl, and 4-carboxy groups.